<template>
  <el-row>
      <el-col :lg="3" :md="6" :xs="0" ></el-col>
      <el-col :lg="18" :md="12" :xs="24">
        <div class="app-header-sticky" :class="{ show: y >78 }">
          a
        </div>
      </el-col>
      <el-col :lg="3" :md="6" :xs="0"></el-col>
    </el-row>
  </template>
  
  <script setup>
  </script>
  
  <style lang='scss'>
  .app-header-sticky {
    width: 100%;
  }
  </style>